CHAPTER 22: NEUROSURGERY: WHAT'S ON THE HORIZON
There are many exciting prospects on the neurosurgical horizon, each aimed at advancing patient care:
· Advanced biomedical imaging (BMI): Brain imaging techniques are becoming more sophisticated and their relatively recent evolution has made an enormous and positive impact upon patient diagnosis, care and outcome. Functional imaging techniques which not only examine brain structure, but also its functions such as regional blood flow and metabolism, and its biochemical signatures, are likely going to be of major significance with time. Still evolving techniques include MRS, functional MRI (fMRI), PET, and intraoperative fluorescence microscopy. The OR environment in many centers is also becoming more advanced, with real-time intraoperative MRI becoming more available, and a film-free hospital environment becoming a reality. Intraoperative image guidance using infrared and laser technology represents a major advance in surgical accuracy and safety, as the surgeon is guided by his or her instruments or microscope lasers with precision through the brain and to the lesion. In the OR, large split-screens simultaneously projecting the real-time view under the operating microscope, the preoperative brain imaging, and the intraoperative image-guidance view are starting to be installed in centers. Wireless technology is also making its mark on the ability of physicians to confidentially access their patients’ studies, including imaging, using handheld and laptop devices. A newer technique known as diffusion tensor imaging (DTI) may also become more widely incorporated into the OR. DTI allows for imaging of important pathways such as the corticospinal tract (CST) responsible for movement of the opposite of the body. The information obtained from DTI can be used in the OR, including in 3D, so that a lesion close to, say, the CST can be removed with more precision, as the imaging data allows the surgeon to see where he or she is operating relative to the location of the CST.
· Virtual reality technology (VRT): The age of real-time immersion of surgeons into a realistic electronic environment is dawning through advances in VRT. The ability to carry out surgery remotely, that is, where the surgeon is not in the same immediate environment as the patient, has already been successfully demonstrated in the fields of general and cardiac surgery. It remains to be seen whether this type of surgery, referred to as telesurgery, will become a practice among neurosurgeons treating patients in geographically remote areas or in a makeshift hospital on a battlefield, or in outer space (Figure 28). Advances in VRT are also enabling surgeons to practice complex surgical approaches prior to the actual operation itself, through realistic, textured, 3D imaging software coupled to desktop computers and hand-held instruments. Finally, the incorporation of a patient’s ghosted brain imaging into the eyepieces of the surgeon’s image-guided operating microscope, similar to technology already available to air force pilots, is anticipated to make a positive contribution to operative safety and success.
· Robotics: Computer-controlled robotic arms are already being used for precision delivery of radiation (as in the Cyberknife® SRS system) and in the setting of functional neurosurgery where stimulating probes are inserted into deep brain structures. The further development of telesurgery will necessarily require hand-in-hand advances in telerobotics, because it will be the remote robotic arms and cameras carrying out the surgery according to the surgeon’s feedback and hand movements (Figure 28).
· Genetic technologies: Using blood and tissue tests to diagnose medical conditions based on their unique genetic signatures is already a reality. Developing and using genetic screening techniques or assays based on simple blood samples to predict the development or outcome of brain conditions is an emerging reality. This represents the anticipated benefits of the Human Genome Project, and the current genomics and proteomics revolutions. Further, ongoing advances in the field of gene therapy will likely, in time, allow a variety of CNS conditions to be effectively treated by appropriate delivery of gene-based medicines aimed at specifically correcting defects at a genetic or molecular level, or at targeting tumor and other abnormal cells while preserving normal brain cells. The fields of genomics, proteomics and gene therapy are overviewed elsewhere (www.brain-aneurysm.com).
